Printing press



T. LOEW PRINTING PRESS March 2, 1937.

Filed Aug. 24, 1933 5 Sheets-Sheet l iNVENTOR BY I 6 V ATTORNEY March 2, 1937. T. LOEW PRINTING PRESS Filed Aug. 24, 1933 5 Sheets-Sheet.- 2

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PRINTING PRESS Filed Aug. 24, 193 3 5 Sheets-Sheet 3 in, Y 4

ATTORNEY March 2, 1937. T, LO W 2,072,116

PRINTING PRESS 7 Filed Aug. 24, .1933 5 Sheets-Sheet 4 Mon 2 W BY g 5 it? i ATTORNEY March 2, 1937.

T. LOEW PRINTING PRESS Filed Aug. 24, 1933 5 Sheets-Sheet 5 INVENTOR M 1494- I .MMZ Q ATTORNEY Patented Mar. 2, 1937 UNITED STATES PATENT OFFICE Application August 24,

21 Claims.

This invention relates to printing presses.

In offset printing, an inked impression is made on a rubber-covered or composition roller and then transferred to the paper. As the offset roller moves across the type, it receives an impression which is the reverse of the type. When this impression is transferred to the paper it is again reversed, so that the impression on the paper reads in the same direction as the type. Offset printing presses therefore require special forward reading type and can not be used with standard type.

Offset printing can be done from standard type if double offset rollers are employed to effect three reversals of the impression in transferring it from the type to the paper, thus producing a final forward reading impression on the paper from standard reverse type.

It is an object of this invention to provide an improved double offset printing press having novel features and combinations of elements which simplify the mechanism of the press and make it economical to manufacture and convenient and advantageous in use.

Another object of the invention is to provide a printing press which prints on the top sheet of a stack of paper and has means for removing the top sheet from the stack after each printing operation, and mechanism for raising the stack, as each top sheet is removed, to maintainthe top of the stack at a substantially constant level. The invention thus eliminates the conventional platen and paper-feeding mechanism.

Another object of the invention is to provide a press having double offset printing means for printing on the top sheet of a stack.

Other objects, features and advantages of the invention will appear or be pointed out as the specification proceeds.

In the accompanying drawings, forming part 4() hereof:

Fig. l is a side elevation of a printing press made in accordance with the invention;

Fig, 2 is a top plan view of the printing press shown in Fig. 1;

Fig. 3 is an end elevation looking to the left in Fig. 1;

Fig. 4 is an enlarged fragmentary diagrammatic detail view of parts of the operating mechanism;

Fig. 5 is an enlarged fragmentary detail view 50 of the mechanism for operating the paper-holding and sheet-removing means; and

Fig. 6 is a sectional view on the line 66 of Fig. 5, and also shows the side frame and a part of the offset rollers with their operating mecha- 55 nism.

1933, Serial No. 686,585

Each side of the printing press frame includes a base II, a side frame l3, a pillar l5 extending from the base to an overhanging end of the side frame, a column l1, and a beam [9 supported by the pillar and column. Both sides of the frame are connected by cross members 2|, 22 (Fig, 3) to form a rigid structure. Certain other parts of the press which will be described connect with both sides of the frame and add to the rigidity of the structure.

The type is held in a chase 23 carried by a chase bed 25 (Fig. 2), which is connected to the side frames l3. Plates or other type substitutes can be used. An ink plate 21 is rotatably supported by the cross member 22.

Referring to Fig. l, a carriage 29 is hung from the side frame I3 by carriage suspension links 30, which are pivotally connected to the side frame and carriage. A truck 32 slides on track 34 formed on the carriage 29. Rollers 35 and 3B are carried by the truck. Gears 3! and 38 are fixed to the rollers 35 and 36, respectively, and these gears mesh with one another so that neither of the rollers can turn without turning the other. The gear 31 meshes with a rack 40, which is fastened to the carriage 29.

The truck 32 is reciprocated on the carriage 29 by a connecting rod 42, which is pivotally con nected at one end to the truck and at its other end to a crank 44. The crank is secured to a main shaft 45, and this main shaft is rotated by power mechanism, such as an electric motor.

The carriage 29 is moved laterally by a link 46 in timed relation to the reciprocating movement of the truck 32. Since the carriage is suspended from links 30, the lateral movement causes the carriage to raise and lower. The link 46 is cam operated by mechanism which will be explained in the description of Fig. 4.

The carriage suspension links 30, the gears 3! and 38, rack 40, connecting rod 42, crank 44 and link 46, shown in Fig. l, are for one side of the printing press. Similar mechanism is located on the other side of the press to avoid twisting strains on the parts when the printing press is in operation.

The roller 35 contacts with the type in the chase 23, and contacts with the lower roller 36 so that an impression which the roller 35 receives from the type is transferred to the lower roller 36. Inking rolls 48 are supported by arms 49 of the truck 32 and move successively across the ink plate 21 and the type during each stroke of the truck.

A stack of paper 52 rests on a bed 54. The

bed slides vertically on the columns I 1 and pillars I5. Paper-guides 56, 51 and 58 hold the stack of paper centered on the bed 54. The positions of these guides can be changed to accommodate paper stacks having different size sheets. The paper-guides 51 are supported by a shaft 60, and have handles 62 which are operated to clamp the paper-guides against sliding on the shaft. When these handles are turned to unclamp the paperguides from the shaft 60, the paper-guides are free to slide into any position on the shafts.

There aresimilar shafts 60 on the other side of the stack, as shown in Fig. 2. These shafts 60 are supported in movable blocks. Fig. 2 shows blocks 64 at one end of the shafts 60. Similar blocks are located at the other ends of these shafts 60. The blocks 64 slide on a transverse beam 66, which connects with both sides of the frame. Each of the blocks 64 can be clamped in any set position on the beam 66 by turning a clamping handle 68. The paper-guides 56 and 58 are "similarly movable to accommodate paper stacks of different sizes. Since all of the paper- I guides can be shifted, the stack of paper can be moved on the bed if itis desirable to change the position of the impression on the paper.

Referring again to Fig. l, the" roller '36 contacts with the top'sheet of the paper stack at each 's'troke'of the truck 32. The impression which the Wiener takes from the type is transferred to i the roller 36, and from this roller to the top sheet of, the paper stack. The machine uses standard "type which makes a forward impression on the roller. 35. The impression is reversed when transferred to the roller 36, and reversed again in its transfer to the paper so that it again reads forr .The top sheet of the stack is removed after each stroke of the press by suction cups 12 opermated by mechanism which will be described. The paper be'df54is raised bychains 15 passing over s procket's.."16. These sprockets are operated to move'the'chains and raise the bed 54 a distance "equal to the thickness of a sheet of paper for 5 each, stroke of the press. This paper-lift mechanism can be adjusted for sheets of different thickness, and will be explained in detail in the 4 description of Fig. 4'.

[Fingers 80 (Fig. 2) hold the top sheet of the 50 stack't'o preventmovement while the impression being made. The fingers 80. are operated by a shaftBZ which is supported by bearings in the paper-guides 56. The shaft 62 is rocked in timed relation to the reciprocating movement of the 55 truck .32 by a flexible shaft 84 which, receives power from a link mechanism which will be explained in .the description of Fig. 5.

flThe ink plate has, a ratchet80 (Fig. 1) which is rotated by a pawl89 pivotally connected to a 60 crank arm 90 secured to a shaft 9|. The shaft 65 carriage29 laterally and for lifting the paper bed upward to raise the stack as the top sheets are removed during the operation of the press.

The link is pivotally'connected at one end to the carriage 29. and atits other end to a sup- 70 porting link I00 which oscillates about a pin I02 [extending from the side frame of the machine. The link 46, has a cam follower I03 operating in agroove I04 of a cam I06; secured to the main shaft 45. As the main shaft 45 rotates, the cam 75 groove l04 ,oau5 s the carriage 29 to move latershaft 45 and cam I06.

ally, and since the carriage is suspended on links 30 (Fig. 1), the lateral movement causes the carriage to raise and lower. The truck 32 makes one complete stroke for each revolution of the main shaft 45, and the cam groove I04 is shaped to cause the carriage to be raised so that the roller 34 contacts with the type when the truck 32 moves in one direction, and to cause the carriage to be lowered so that the roller 36 contacts with the top sheet of the paper stack when the truck 32 moves in the other direction.

Referring again to'Fig. 4, the cam groove I04 also operates the mechanism for raising the bed 54 and stack of paper. The chains I5 pass over sprockets 16 on a shaft H0. The shaft and sprockets are turned by a worm wheel I I2, which is secured to the shaft and driven by a worm gear H4.

The worm gear H4 is driven from a ratchet wheel I I5 through bevel gears H6 and a shaft I I8. The ratchet wheel I I5 turns on a shaft I20 supported by the side frame of the press. .A pawl I22 operates the ratchet and another pawl I24 holds the ratchet against reverse rotation. The

pawls I22 and 124 are both moved into nonoperative position when the bed 54 is to be lowered for a new stack of paper.

The pawl I22 is supported by a link I28 which oscillates on the shaft I20. The pawl is operated by a link I30, which is pivotally connected to aclamp I32. This clamp fits a. curved arm of a lever I34 and can be held in any desired position on the lever by a clamping screw I36. A stud I38 extending from the side frame of the t on on the lever by a clamping screw I36. A

cam follower I on the upper arm of the lever I34 fits in the cam groove I04. Thus this cam groove operates both the carriage 29 and the mechanism for raising the paper bed 54.

Moving the clamp I32 closer to the stud !38 reduces the stroke of the link I30 and causes the pawl I22 to move the ratchet I I5 through a smaller angle for each revolution of the main The mechanism is thus set to regulate the amount of rise of the paper bed for each printing operation of the press. When the sheets of paper are thin, a very gradual rise of the paper bed maintains the top of the stack at a substantially constant level, but with thicker sheets of paper the height of the stack is reduced more by the removal of a top sheet, and it is therefore necessary to raise the paper bed faster.

Fig. 5 shows the mechanism for oscillating the flexible shaft 84 and for removing the top sheet from the stack after each printing operation. An eccentric I50 on the main shaft has a groove I52. A cam follower I54 on one end of a bell crank I56 fits the groove I52 and causes the bell crank to rock about a stud I53, as the eccentric rotates. The stud I is supported by the side frame of the press.

The other end of the bell crank I56'has a pivotal connection I60 to the upper link of a toggle I62. The lower link of the toggle oscillates on a stud I64 projecting from the side frame of the press. A slotted link I66 is pivotally connected at one end to the joint of the toggle, and at the other end to a crank arm I68, which is fastened to a shaft I10. This shaft I10 extends through the side frame, which serves as a bearing for the shaft, and is connected to the flexible shaft 84.

A gear sector I12 is rotatably supported on an axle I14. A stud I18 on the gear sector extends into the slot in the link I66, so that vertical movement of the link I66 imparts rotary move ment to the gear sector II2.

Referring back to Fig. 2, there are bars I82 on both sides of the press. These bars are spaced from the side frames I3 and each bar supports a block I84. Each of these blocks I85 is slidable along its bar I82, and is clamped against sliding by clamping means operated by a handle I86. A shaft I88 has its opposite ends journaled in the blocks I84. Yokes I98 are fastened to the shaft I 88 and these yokes support arms I92, to which the suction cups I2 are connected. The blocks I84 are moved into different positions along the bars I82 to cause. the suction cups 12 to grip the edge of the paper regardless of its size.

'One of the arms I92 and its suction cup I2 are shown in Fig. 5. A pinion I96 on the end of the shaft I88 meshes with the gear sector I'I2 so that rotary movement of the gear sector causes a rotation of the shaft I88. The axle I14 of the gear sector is carried by the block I84.

The yokes I90 are of such length, and the upper ends of the arms I92 are so shaped, that, as the shaft I88 rotates, the arms I92 are first raised vertically and then rotated up and out,

carrying with them the top sheet of paper which is held by the suction cups I2. A suction hose I98 connects each suction cup I2 with an air valve (not shown) for shutting off the suction when the arms are at the top of the stroke, so that the paper is released. Such valves are well known in the art and can be operated by the shaft I88.

The slot in the link I66 permits the block I84 to be moved along the bar I82 to position the arms I92 and suction cups I2 to grip the edges of different size sheets without affecting the operation of the gear sector II2 by the vertical movement of the slotted link I66.

The operation of the printing press is as follows:

The main shaft 45 is power-driven to rotate the crank 44 and cam I06. The crank causes the truck 32 to move to and fro on the carriage 29. The groove in the cam I66 is shaped to move the carriage 29 toward the right in Fig. 1, so that it is raised by the links 30 during the time that the truck 32 is moving in one direction, thus causing the roller 35 and the inking rolls 48 to roll across the face of the type.

The groove of the cam I66 moves the carriage 29 to the left into the lowered position shown in Fig. 1, where it remains while the offset roller 36 rolls across the top sheet of the paper stack 52.

While the top sheet is being printed it is held against movement by the fingers 80. After the sheet is printed, the fingers are moved away from the paper by the shaft 82, which is rotated by the flexible shaft 84. The flexible shaft is operated from the shaft I'II], which is oscillated by the mechanism shown in Fig. 5.

After the fingers 80 release the paper, the top sheet is gripped by the suction cups I2 and removed from the stack. The pawl and ratchet mechanism shown in Fig. 4 turns the sprockets i6 enough at each stroke of the press to raise the bed 54 and stack of paper by a distance substantially equal to the thickness of a sheet of paper, thus maintaining the top of the stack at a substantially constant level during the operation of the press.

The invention can be employed for printing on boxes or other objects having a relatively plane surface, by successively placing the boxes or objects on the bed 54 in place of the stack of paper. The impression is made on the top side of the box or object in the same way as the top sheet of the stack is printed. The feed mechanism for raising the bed further with each printing operation is not necessary when printing on boxes.

The preferred embodiment of the invention has been described, but changes and modifications may be made, and various features of the invention may be used alone or in combination with other features, without departing from the invention as defined in the claims.

Iclaim:

1. An offset printing press including an impression receiving roller; means for holding a stack of paper; means for moving the roller into contact with the top sheet of the stack and across the sheet to print the impression on said sheet; and means for removing the top sheet from the stack after each printing operation.

2. An offset printing press including an impression receiving roller; a bed for supporting a stack of paper; means for moving the roller into contact with the top sheet of the stack and across the sheet to print the impression on said sheet; means for removing the top sheet from the stack after each printing operation; and mechanism for raising the bed to maintain the top of the stack at a substantially constant level.

3. In a printing press, means for printing on the top sheet of a stack of paper; means for holding the sheet against movement during printing; and mechanism for releasing the holding means and removing the top sheet from the stack after the top sheet is printed.

4. A printing press including a bed for supporting a stack of paper; guides supported independently of the bed and in position to extend along the sides of the stack to prevent it from shifting laterally; means for changing the positions of the guides to accommodate stacks having larger sheets; apparatus for printing on the top sheet of the stack; and mechanism for removing each sheet from the stack after it is printed.

5. A printing press including a bed for supporting a stack of paper; guides extending along the sides of the stack to prevent it from shifting laterally; apparatus for printing on the top sheet of the stack; mechanism for removing each sheet from the stack after it is printed; mechanism for raising the bed as the top sheets of the stack are removed so that the top of the stack remains at a substantially constant level; guide-supporting means which remain stationary during the raising of the bed whereby the guides remain in substantially fixed relation to the top of the stack; and means for changing the positions of the guides to accommodate stacks having larger sheets.

6. A printing press comprising a chase for holding type; a truck; two offset rollers carried by the truck; mechanism for moving the truck to alternately roll one of the offset rollers across the type and the other offset roller across a sheet of paper, said rollers contacting with one another to transfer the impression from the type-contacting roller to the paper-contacting roller.

7. In a printing press of the oifset type, a carriage; a truck movable on the carriage between the type and the paper to be printed; ofiset roller means carried by the truck and movable across the face of the paper; mechanism for raising and lowering the carriage to move the offset roller means alternately into contact with the type and paper; and mechanism for reciprocating the truck on the carriage in timed relation to the operation of the mechanism for raising and lowering the carriage.

8. A printing press comprising a frame; a carriage; links pivotally connected to the carriage and frame to support the carriage from the frame; mechanism for reciprocating the carriage to oscillate said links and cause the carriage to move toward and from the frame; a truck supported by the carriage; offset roller means carried by the truck; and mechanism for reciprocating the truck on the carriage in timed relation to the operation of the mechanism for raising and lowering the carriage.

. 9. In a printing press, a carriage; printing means on the carriagefor printing on the top sheet of a stack of paper; mechanism for raising the stack of paper; mechanism for causing the carriage to raise and lower; and a common operating cam for both of said mechanisms.

10. In a printing press of the offset type, a frame; a carriage supported by thev frame and movable with respect to said frame; tracks on the carriage; a truck supported by the tracks; means for holding type; other means for supporting the work to be printed; offset roller means carried by the truck; and mechanism for moving the truck with respect to the carriage to move said offset roller means across the faces of the type and work.

11. In a printing press of the offset type, a frame; a carriage supported by the frame and movable with respect to said frame; tracks on the carriage; offset rollermeans; inking rolls; a truck supported by the tracks and carrying said offset roller means and inking rolls; means for holding type; other means for supporting the work to be printed; and mechanism for moving the truck to and fro along the tracks to move the inking rolls across the type and the offset roller means across the faces of the type and work.

12. In a printing press, an offset roller for receiving an impression from type; another offset roller for transferring the impression from the first offset roller to a sheet of paper; a common truck carrying both offset rollers and movable Vertically and horizontally a gear connected with each roller and meshing with the gear of the other roller to cause said rollers to turn together, and means for causing the rollers to turn during the movement of the truck.

13. In a printing press, a carriage; a truck supported by the carriage; mechanism for moving the truck to and fro on the carriage; an offset roller for receiving an impression from type; another offset roller for transferring the impression from the first offset roller to a sheet of paper; bearings on the truck for both of the offset rollers; a gear connected with each roller and meshing with the gear of the other roller to prevent slippage between the contacting faces of said rollers; and a rack on the carriage in position to mesh with one of said gears for all positions of the truck as it moves to and fro on the carriage.

14. A printing press comprising a bed for supporting a stack of paper; means for printing on the top sheet of the stack; mechanism for removing the top sheet from the stack after each operation of the printing means; mechanism for raising the bed and stack as the top sheets of the stack are removed so that the top of the stack remains at a substantially constant level; and means for changing the rate of operation of the stack-raising mechanism to correspond to sheets of different thickness.

15. A printing press comprising a bed for supporting a stack of paper; guides extending along the sides of the stack to prevent it from shifting laterally; chains supporting the bed; sprockets over which the chains pass; means for printing on the top sheet of the stack; mechanism for removing the top sheet from the stack after each operation of the printing means; and mechanism for rotating the sprockets to cause the bed to rise and maintain the top of the stack at a substantially constant level as sheets are removed after each printing operation.

16. A printing press comprising a bed for supporting a stack of paper; means for printing on the top sheet of the stack; mechanism for removing the top sheet from the stack after each operation of the printing means; mechanism for raising the bed and stack as the top sheets of the stack are removed so that the top-of the stack remains at a substantially constant level, said mechanism for raising the bed and stack including pawl and ratchet means, a cam-operated lever for moving the pawl, and means for changing the effective length of said lever to vary the rate at which the bed and stack are raised.

17. A double offset printing press comprising a roller for receiving'an impression from type, a transfer roller in contact with the first roller for transferring the impression from the first roller to the top sheet of a stack of paper, a bed for holding the stack of paper, means for removing the top sheet from the stack after each printing operation, and feed mechanism for bringing the rollers and the bed progressively closer to allow for the diminishing height of the stack of paper as the successively printed sheets areremoved.

18. A printing press comprising means forprinting on the top sheet of a stack of paper, a

' bed for supporting the stack of paper, means for removing each sheet from the stack after it is printed, mechanism for moving the bed to maintain the top of the stack at a substantially constant level as successively printed sheets are removed, and guides extending along the sides of the stack to prevent it from shifting laterally, said guides being separate from the bed and stationary during the movement of the bed and stack, and means for changing the positions of the guides to accommodate stacks having sheets of different size.

19. In a printing press, means for printing on a stack of paper, and mechanism for automatically removing the top sheet from the stack after each printing operation including means for gripping the sheet near its edge, control means which can be set to cause the gripping means to grip near the edge of sheets of various sizes, and driving mechanism constructed and arranged to operate the gripping means for all positions of said control means.

20. A printing press including means for printing on the top sheet of a stack of paper, a bed on I which the stack rests, mechanism for raising the bed progressively with each printing operation, guides on all four sides of the stack of paper, stationary supporting means for the guides so that said guides do not rise with the stack and bed, said supporting means being located below the top of the stack when the top sheet of the stack is in position to receive an impression from the printing means, and means for changing the positions of all of the guides so that the stack can be shifted with respect to the printing means to change the position of the impression on the paper.

21. A printing press comprising a bed on which the work rests with the surface to be printed in a substantially fixed plane, roller means which reciprocate transversely to the face of the work to be printed and which are located at a substantial distance above the bed for taking an impression from type and transferring it to the top surface of the work, mechanism for moving said roller means across the type and thereafter moving said 5 roller means into rolling contact with the top surface of the work to be printed.

THEODORE LOEW. 

